Conventional micropumps are used for controlled and highly precise dispensing of conventional insulin. For example, European Patent No. EP 1 651 867 Bi describes a micropump, which is designed as a complex layer system.
Conventional micropumps usually include at least one inlet valve and at least one outlet valve. These micropumps have a valve member, usually piston-shaped, which is adjustable between an open position and a closed position and is in a more or less sealing contact with a stationary valve seat in the closed position. There is the problem in general of suboptimal sealing of a valve in its closed position, which is sometimes manifested in unacceptable leakage rates and/or reduced operating pressures.